Ranked Choice Voting: Does a mathematical algorithm make for better elections?

Illustration for article titled Ranked Choice Voting: Does a mathematical algorithm make for better elections?

Yesterday, San Fransisco residents had a number of choices to make in their mayoral election. Using the new Ranked Choice Voting system, voters were called on to select their top three candidates from a field of sixteen instead of casting a vote for a single candidate. What exactly is Ranked Choice Voting, how does it work, and is it a better way conduct elections?


How does Ranked Choice Voting work?
In Ranked Choice Voting, the first choices of all voters are counted. If one candidate receives 50% of the votes, that candidate wins the election. However, if a candidate does not receive a majority of votes cast, the candidate with the least amount of first place votes is eliminated. The eliminated candidate's first place votes are removed, with the second choice of the voters for the eliminated candidate "counting" in the next round. The votes are tabulated again, with a series of eliminations occurring until one candidate receives a majority of the eligible votes. In case that verbal explanation didn't make sense, the diagram below should explain it well.

Illustration for article titled Ranked Choice Voting: Does a mathematical algorithm make for better elections?

Instant runoff
With a large field of candidates, one candidate is unlikely to obtain a majority of votes, leading to at least one runoff election. Runoff elections are costly and are oft plagued by small turnout, but the Ranked Choice Voting system eliminates the need for runoffs - one single election results in a victor. The results may take a few days to tabulate , but voting machines can quickly be configured to be used in a Ranked Choice system.

If it is good enough for the Hugo Awards and the Oscars...

Ranked Choice Voting has been in use for popular, apolitical elections for several years. The Hugo awards are currently decided by Ranked Choice Voting, and members of the Academy of Motion Picture Arts and Sciences use the system to select the Oscar winner for Best Picture. Minneapolis-St. Paul and Portland, Maine have used it for regional elections in the past few years, while Ireland uses the system for its Presidential elections. Ireland's 1990 Presidential election posed one interesting result implicit within the Ranked Choice system - the winner of the first round of voting, who did not have 50% of the votes, lost the election once votes were re-assigned in a second round. This is one of the more difficult to stomach aspects of Ranked Choice Voting, possibly hampering the system for major elections, or, at the very least, necessitating an informed voting public.

An end to dirty politics?
Third party candidates in tight elections would no longer be spoilers, especially in close elections. However, voters that desire a third party candidate would still have their voice heard, while maintaining the ability to influence the election through the trickle down effect of ranked voting. Stanford mathematician Keith Devlin, when asked about Ranked Choice Voting and its impact on partisanship, said,

The voters will make the selection, but the math we choose can shape the kind of government we get. Do we want politics to be about partisanship and fighting, where half the electorate will always end up as losers and we just keep seesawing between the two, or do we encourage cooperation and compromise, where no one gets everything but everyone gets something?"


Under this system, politicians would no longer be fighting for your single vote, so, in theory, directed negative attacks would diminish. Elections could be more about issues and less about skeletons in the closet, with politicians putting on their best and most compromising face, with the hopes of being your second or third choice, if not your first.

An educated voting public is necessary
Ranked Choice Voting certainly seems like a good idea for elections with a large number of candidates, efficiently eliminating candidates that garner a lower number of votes without biasing voters against a more appealing candidate. Will we see it anytime soon in our President elections? Probably not, unless the public can be sufficiently informed of the possible outcomes, but a well informed electorate could greatly benefit from the system and its positive influence on campaigning.


Top image from altered from Vavara, with diagram coming from a CC source. Image of the Hugo Award courtesy of the World Science Fiction Society. Sources linked within article.

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Michael Busuttil

Unless I'm misunderstanding the explanation, this is basically the process for elections in Australia too. You rank the candidates in order, one to whatever, and it counts first votes; if no-one has won then the lowest ranking candidate is kicked out and their second preferences are counted; repeat until a party wins.

In US Presidential elections, then do you literally just pick "Democrat" or "Republican" and that's all?